Non-Native Species in Aquaculture: Terminology, Potential Impacts, and the Invasion Process

Zebra mussels clog water pipes of power plants in the Great Lakes region. Boaters on the Mississippi River are injured by jumping carp. Predatory and scary-looking snakeheads prowl the Potomac River. These are just a few examples of an issue that has become a global problem. Hundreds of aquatic species have been moved outside their native ranges by humans. Some species are moved incidentally as hitchhikers, as in ballast water or on boat trailers. However, many economically important activities such as aquaculture, the aquarium and water garden trade, the live seafood trade, and commercial and recreational fishing can serve as pathways for the introduction of non-native aquatic species. Many non-native species of crops, livestock and sport fish are economically beneficial and socially important. Unfortunately, some introduced species become pests and may cause economic losses, prey on and compete with native species, alter aquatic habitats, and invade parks and preserves. The problem of non-native species has attracted increasing attention from the media, governmental agencies, and non-governmental organizations. In the United States, substantial amounts of public resources have been committed to eradication and control programs. For example, about $10 million to $15 million are spent annually controlling sea lamprey (Petromyzon marinus) in the Great Lakes. There is a growing bureaucracy of agencies and interagency groups (e.g., National Invasive Species Council, Aquatic Nuisance Species Task Force) that have coordination, management or regulatory responsibilities relative to non-native aquatic species. There are frequent media stories highlighting the dangers of Asian carp, snakeheads, zebra mussels and other high-profile non-native species. In addition, some environmental advocacy groups have adopted invasive species as a “hot button” issue.